package org.i_plus.controller;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 * Servlet implementation class SecurePic
 */
@WebServlet("/SecurePic")
public class SecurePic extends HttpServlet {
	private static final long serialVersionUID = 1L;
	public static final char[] chars = 
		{'2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','K','L','M','N','P','Q','R','S','T','W','X'};
	public static Random random = new Random();

	public static String getRandomString() {
		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < 6; i++) {
			buffer.append(chars[random.nextInt(chars.length)]);
		}
		return buffer.toString();
	}

	public static Color getRandomColor() {
		return new Color(random.nextInt(255), random.nextInt(255), random
				.nextInt(255));
	}

	public static Color getReverseColor(Color c) {
		return new Color(255 - c.getRed(), 255 - c.getGreen(), 255 - c
				.getBlue());
	}
	protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		res.setContentType("image/jpeg");		
		HttpSession session = req.getSession();
		String randomString = getRandomString();
		session.setAttribute("SecureNumber", randomString);

		int width = 100;
		int height = 30;

		Color color = getRandomColor();
		Color reverse = getReverseColor(color);

		BufferedImage bi = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = bi.createGraphics();
		g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
		g.setColor(color);
		g.fillRect(0, 0, width, height);
		g.setColor(reverse);
		g.drawString(randomString, 18, 20);
		for (int i = 0, n = random.nextInt(100); i < n; i++) {
			g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);
		}
		
		ServletOutputStream out = res.getOutputStream();
		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		encoder.encode(bi);
		out.flush();
		
	}
}
